• Journal of Life Science
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• v.20 no.7
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• pp.1143-1150
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• 2010

The antibacterial activity of methanol extracts from 70 kinds of oriental medicinal herbs on four strains of Staphylococcus aureus and S. epidermidis was investigated. The results showed that C. japonica, C. sappan, R. javanica, R. tanguticum, and S. miltiorrhiza had an antibacterial activity on all the strains used. Among these, C. japonica and R. javanica, which showed excellent antibacterial activity, were extracted with water, ethanol, methanol, and ethyl acetate for further study of antibacterial activities. The results showed that the boiled water extract of C. japonica had the best antibacterial activity. Assuming that the antibacterial activity of C. japonica originated from berberine, which has been reported many times, the berberine content of the boiled water extract of C. japonica was analyzed and the result was 13.88%. To compare the antibacterial activity of berberine with that of other antibiotics, berberine chloride and three other kinds of antibiotics were investigated, which showed that berberine chloride had an antibacterial activity on KCCM 35494 S. epidermidis only when the concentration was higher than 600 mg/l, and it did not show antibacterial activity in the other strains. Based on these results, it was concluded that the antibacterial activity of the boiled water extract of C. japonica on the strains used in this study originated from high concentration of berberine or substances other than berberine. Therefore, identification of the substance will be necessary.

• The Journal of Korean Society for School & Community Health Education
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• v.22 no.4
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• pp.49-60
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• 2021

Objectives: Laboratories have various latent physical, chemical, biological, and ergonomical factors according to the diversification and fusion of research and development activities. This study aims to investigate the chemical exposure concentrations of college laboratories and evaluate their health risks, and use them as basic data to promote the health of college students. Methods: The sampling and analysis of harmful chemicals in the air in laboratories were performed using Method 1500 of the U.S. National Institute for Occupational Safety and Health (NIOSH)의 Method 1500. The harmful chemicals in the laboratories were divided into carcinogenic and non-carcinogenic chemicals. Risk assessment was performed using the cancer risk (CR) for carcinogenic chemicals and using the hazard index (HI) for non-carcinogenic chemicals. Results: The harmful chemicals in college laboratories consisted of acetone, diethyl ether, methylene chloride, n-hexane, ethyl acetate, chloroform, tetrahydrofuran, toluene, and xylenes. They showed the highest concentrations in laboratories A (acetone 0.001~2.34ppm), B (chloroform 0.95~6.35ppm), C (diethyl ether 0.08~8.68ppm), and D (acetone 0.07~14.96ppm). The risk assessment result for non-carcinogenic chemicals showed that the HI of methylene chloride was 2.052 for men and 2.333 for women, the HI of N-hexane was 4.442 for men and 5.05 for women. Thus, the HI values were higher than 1. The risk of carcinogenic chemicals is determined by an excess cancer risk (ECR) value of 1.0×10^-5, which means that one in 100,000 people has a cancer risk. The ECRs of chloroform exceeded 1.0×10^-5 for both men and women, indicating the possibility of cancer risk. Conclusion: College laboratories showed the possibility of non-carcinogenic health risks for methylene chloride, n-hexane, tetrahydrofuran (THF), toluene, and xylenes, and carcinogenic health risks for chloroform, methylene chloride. However, this study used the maximum values of measurements to determine the worst case, and assumed that the subjects were exposed to the corresponding concentrations continuously for 8 hours per day for 300 days per year. In consideration of the nature of laboratory environment in which people are intermittently exposed, rather than continuously, to the chemicals, the results of this study has an element of overestimation.

• Bulletin of the Korean Chemical Society
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• v.27 no.9
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• pp.1439-1444
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• 2006

A $Cu^{2+}$ ion-selective membrane microelectrode has been fabricated from poly vinyl chloride (PVC) matrix membrane containing a new symmetrical hexadentate Schiff,s base 2-{1-(E)-2-((Z)-2-{(E)-2-[(Z)-1-(2-hydroxyphenyl)ethylidene]hydrazono}-1-methylpropylidene)hydrazono]ethyl}phenol (HDNOS) as a neutral carrier, Potassium tetrakis(4-chlorophenyl) borate (KTpClPB) as an anionic excluder and o-nitrophenyloctyl ether (NPOE) as a plasticizing solvent mediator. The microelectrode displays linear potential response in the concentration range of $1.0\;{\times}\;10^{-5}-1.0\;{\times}\;10^{-11}$ M of $Cu^{2+}$. The microelectrode exhibits a nice Nernstian slope of 25.9 ${\pm}$ 0.3 mV $decade^{-1}$ in the pH range of 3.1-8.1. The sensor has a relatively short response time in whole concentration ranges ($\sim$5 s). The detection limit of proposed sensor is $5.0\;{\times}\;10^{-12}$ M (320 pg/L), and it can be used over a period of eight weeks. The practical utility of the sensor has been demonstrated by using it as an indicator electrode in the potentiometric titration of $Cu^{2+}$ with EDTA. The proposed membrane electrode was used for the direct determining of $Cu^{2+}$ content in black and red pepper, and in waste water samples.

• Korean Journal of Pharmacognosy
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• v.46 no.3
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• pp.234-242
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• 2015

Allium hookeri (Liliaceae), native to India is widely cultivated in Korea lately as a medicinal plant. This study was performed to evaluate the antioxidant and lifespan extending effects of the root of A. hookeri. Methanol extract from the root of A. hookeri was successively partitioned as methylene chloride, ethyl acetate, n-butanol and H₂O soluble fractions. Antioxidant effects of the fractions were measured by measuring the radical scavenging effect on 1,1-diphenyl-2-picrylhydrazyl (DPPH), and superoxide quenching activities. Lifespan extending effects of the fractions were investigated using Caenorhabditis elegans model system. In addition, stress resistant, superoxide dismutase (SOD) and catalase activities, and intracellular reactive oxygen species (ROS) levels were also studied. Furthermore, we had investigated aging-related factors such as reproduction, food intake, growth and movement of C. elegans to find any sample-induced significant change. Our results revealed that ethyl acetate soluble fraction from the root of A. hookeri showed the most potent antioxidant and lifespan extending effects, and this fraction elevated the most potent SOD and catalase activities of worms, and reduce intracellular ROS accumulation.

• Korean Journal of Pharmacognosy
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• v.46 no.3
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• pp.214-222
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• 2015

Recently, many studies have focused on the aging and oxidative stress. Several papers reported that Vigna angularis has various biological properties including antiaging, antioxidative and anti-inflammatory activities. Methanol extract from the red bean sprouts was successively partitioned as n-hexane, methylene chloride, ethyl acetate, n-butanol and H₂O soluble fractions. We had studied lifespan extending and stress resistant effects of the fractions using Caenorhabditis elegans. Superoxide dismutase (SOD), catalase activities, and intracellular reactive oxygen species (ROS) levels were also investigated. Moreover, we had studied to find any significant change in aging-related factors such as reproduction, food intake, growth and movement of C. elegans. Our results represent that ethyl acetate fraction showed the most potent lifespan extending and stress resistant effects, and this fraction was able to elevate SOD and catalase activities of worms, and reduce intracellular ROS accumulation.

• Korean Journal of Pharmacognosy
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• v.46 no.1
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• pp.84-92
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• 2015

Tyrosinase is a key enzyme to control the biosynthesis of melanin pigments and has two enzyme activities, namely of 1-tyrosine hydroxylase and of 1-dopa oxidase. Thus, tyrosinase is regarded as a target in skin-whitening and therapeutic intervention of local hyperpigmentation diseases. We have tested tyrosinase inhibitory activity on the water extracts of 50 species oriental medicinal plant. Among them, five medicinal plants, Linderae Radix, Clematidis Radix, Cinnamomi Cortex Spissus, Fritillariae Thunbergii Bulbus and Bulbus Fritillariae Cirrhosae were investigated strong inhibition effect. Five medicinal plants were fractionated using organic solvents (methylene chloride, ethyl acetate, n-butanol, water). Cinnamomi Cortex Spissus (ethyl acetate fraction) was investigated strong inhibition effect. Tyrosinase inhibitory activity below $IC_{50}\;40{\mu}g/ml$ is confirmed in five herbal plants that are Linderae Radix, Clematidis Radix, Cinnamomi Cortex Spissus, Fritillariae Thunbergii Bulbus and Bulbus Fritillariae Cirrhosae. Tyrosinase inhibitory levels ($IC_{50}\;{\mu}g/ml$) of each plants were 15.56, 35.02, 25.14, 15.20 and 39.77. We also investigate the effect of effective plant's fraction. in dose of $100{\mu}g/ml$, Cinnamomi Cortex Spissus (P-36) EtOAc fraction significant inhibitory effect over 50%. Clematidis Radix (P-35) and Cinnamomi Cortex Spissus (P-36) MC fraction inhibit tyrosinase each 36.60% and 43.21%. inhibitory rates of Fritillariae Thunbergii Bulbus (P-40) EtOAc and $H_2O$ fraction are 31.40% and 31.51%. Bulbus Fritillariae Cirrhosae (P-45) BuOH fraction regulate tyrosinase activity to 37.71%. We examined tyrosinase inhibitory activity of natural products and these results suggest that several herbs have potential as a new whitening material.

• Korean Journal of Pharmacognosy
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• v.47 no.1
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• pp.55-61
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• 2016

Antioxidant effects and nuclear factor E2-related factor-2 (Nrf-2) signal pathway of methanol extract and 4 fractions [n-hexane, methylene chloride, ethyl acetate (EtOAc), and n-butanol fractions] from Petasites japonicus were investigated. The EtOAc fraction showed highest polyphenol and flavonoid contents among other fractions. In addition, EtOAc fraction showed stronger scavenging activity against superoxide anion radical than other fractions. Furthermore, we investigated antioxidants effects of the EtOAc fraction under cellular system using $LLC-PK_1$ cells. The EtOAc fraction dose-dependently increased the antioxidant protein expressions of heme oxygenase 1 (HO-1) and thioredoxin reductase 1 (TrxR1) known to be involved in oxidative stress, through activation of Nrf-2. The treatment of EtOAc fraction ($100{\mu}g/mL$) led to the elevation of the high expression of Nrf-2-dependent factor such as HO-1 and TrxR1. These results indicated that the EtOAc fraction of P. japonicus showed high antioxidant activity by regulation of Nrf-2 signaling pathway.

• Journal of the Korean Chemical Society
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• v.38 no.9
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• pp.676-681
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• 1994

Diels-Alder adducts, carbacephems were obtained when 4-acetoxyazetidine-2-one or (3R,4R)-4-acetoxy-3-[(1R)-1-(tert-butyldimethylsilyloxy)ethyl]azetidin-2-one was reacted with 2-(tert-butyldimethylsilyloxy)-1,3-butadiene or with 3-(tert-butyldimethylsilyloxy)-1,3-pentadiene. When tert-butyldiemethylsilyl acrylate was used as the diene, products in which was acetoxy group of 4-acetoxyazetidin-2-one derivatives was substituted by an acryloyloxy group were isolated. When the same reaction was carried out with 4-phenylsulfonylazetidin-2-one as a dienophile with 2-(tert-butyldimethylsilyloxy)-1,3-butadiene, 4-phenylsulfoyl-2-butanone was obtained instead of the expected carbacephem. When dimeric form of thiochalcone was reacted with 4-acetoxyazetidin-2-one in the presence of zinc chloride, the $\beta-lactam$ ring of the azetidin-2-one was destructed and no product was isolated. Also, the reaction of 2-trimethylsilyloxy-1-aza-1,3-butadiene, which was obtained from N-methylacrylamide by treatment of trimethylsilyl trifluoromethanesulfonate in the presence of triethylamine, with 4-acetoxyazetidin-2-one did not give any products.

• YAKHAK HOEJI
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• v.58 no.5
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• pp.294-299
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• 2014

In this study, we investigate anti-allergic and anti-inflammatory effects of Leonurus sibiricus seed (LSS) extract in basophilic leukemia RBL-2H3 cells. To identify anti-allergic actions of LSS, the degranulation was evaluated in IgE and DNP-BSA stimulated RBL-2H3 cells. At the concentration of $100{\mu}g/ml$ of methanol (MeOH) extract and Methylene chloride (MC) and Ethyl acetate (EtOAc) fractions, the degranulation was significantly inhibited 16.7%, 16.7% and 27.9% respectively. And then, to assess anti-inflammatory effects of LSS, IL-4 and IL-13 mRNA level were detected in PMA/ionomycin (PI)-induced RBL-2H3 cells and cell proliferation and IL-4 mRNA level in isolated splenocytes from Balb/c mice. LSS MeOH extract and MC and EtOAc fractions significantly decreased the level of IL-4 and IL-13 mRNA in PI-induced RBL-2H3 cells and showed inhibitory effects on cell proliferation and expression of IL-4 mRNA level in mouse splenocytes. Taken together, these results suggest that LSS has potential anti-allergic and anti-inflammatory effects and EtOAc fraction is the most effective in regulating immune responses.

• Elastomers and Composites
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• v.39 no.3
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• pp.234-243
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• 2004

The elastomeric and conductive polyurethane (PU) films were prepared by poly(propylene glycol) (PPG), toluene 2,4-diisocyanate, 3-methylthiophene (3-MT) at various preparation conditions, such as the reaction time, the $FeCl_3$ concentration, the weight ratio of the 3-MT to PU and the reaction temperature for the diffusion-oxidative reaction. The conductive poly (3-methylthiophene) (PMT) layers via the diffusion-oxidative reaction of 3-MT and ferric chloride were formed by immersing the film in organic solution of $FeCl_3$/ethyl acetate. The preparation conditions greatly affected the electrical conductivity of the 3-MT/PU composite. The effects of the reaction time and temperature on morphology and surface free energy were investigated by scanning electron microscopy (SEM) analysis and contact angle measurement, respectively. The conductivity of the composite was as high as 42 S/cm.